This invention relates to an apparatus for processing a melted glass stream into a melted glass lump of a predetermined volume.
On manufacturing a glass product, such as glass tableware, a glass bottle, an optical glass lens, or the like, it is necessary to cut a melted glass stream into a melted or fused glass lump of a predetermined volume and to introduce the melted glass lump into a die. The melted glass stream is discharged from a melting or fusion furnace and runs at a first speed in a first direction which may be, for example, in the direction of gravity, namely, a vertical direction. A cutting apparatus or a shear is generally used to cut such a melted glass stream into the melted glass lump.
A conventional cutting apparatus comprises a cutting section formed by first and second cutter portions or blades to cut the melted glass stream at predetermined intervals and a driving section for driving the first and the second cutter portions in a second or horizontal direction perpendicular to the first direction. The first and second cutter portions are moved in the horizontal direction to be repeatedly opened or closed. When the first and the second cutter portions are closed, the melted glass stream is cut into the melted glass lump of a predetermined volume. The melted glass lump falls down in the direction of gravity at a second speed faster than the first speed because no influence is exerted by the viscosity of the melted glass stream. The second speed may depend on gravitational acceleration. After closure of the first and the second cutter portions, the first and the second cutter portions are opened at the predetermined position. After lapse of a predetermined interval, the first and the second cutter portions are closed again to cut the melted glass stream into the melted glass lump of the predetermined volume. Each melted glass lump is introduced into the die and is processed into the glass product by press processing.
In the conventional cutting apparatus, cut chips inevitably remain on both the first cutter portion and the second cutter portion and are irregularly hardened on the first and the second cutter portions into a plurality of glass pieces after the above-mentioned cutting operation. Such irregular glass pieces are traced or transferred on a cut end of the melted glass lump in the form of an irregular cut mark. In addition, the glass pieces undesirably enter the melted glass lump. Such entering of the glass pieces into the melted glass lump gives rise to a plurality of bubbles in the melted glass lump. Cut marks and bubbles will be collectively called shear marks.
Accordingly, the shear marks should be removed after the glass product is manufactured. However, it is practically difficult to remove the shear marks from the glass product. This means that undesirable remnants are unavoidably left in the glass product due to the shear marks and reduce the quality of the glass product. At any rate, the use of the conventional cutting apparatus causes a damage to occur in the glass product and deteriorates the quality of the glass product.